I didn't manage to work on this any more yesterday, but the rest of this chapter is my remaining goal for the rest of the day. I'll jot down a few words for now here and then hopefully keep working elsewhere...
But to get the full picture of what Paul really thought, we cannot simply read Romans 9 by itself. If we do not go on to read Romans 11 we will end up with a skewed sense even of Paul's view toward Israel. For example, one perspective we sometimes find today is called "replacement theology." It is the idea that the church has now completely replaced Israel within God's plan. This view gets a lot of mileage out of Romans 9:6: "not all who are descended from Israel are Israel." Such individuals see the church as the true Israel, and only ethnic Jews that believe are part of true Israel along with Gentiles who have believed. Certainly they do not see any place in God's plan for the nation of Israel or non-believing Jews today.
This perspective likely contains some truth, but it is certainly not the whole story. You can only get this impression if you lift Romans 9:6 out of Paul's broader discussion. Romans 11 in particular makes it clear that Paul saw the dominance of Gentile Christianity as a temporary thing and that, in fact, ethnic Israel itself for the most part would eventually believe in Jesus. It has not happened yet, and Paul himself might be surprised not only at how much time has passed but also to know that God allowed Israel to be destroyed for almost two thousand years. But we cannot let these complications stand in the way of listening to what Paul was saying. We have to let him say what he said and then deal with it in our theology.
Has God rejected his people, Paul asks in Romans 11:1? No. Paul himself is an Israelite, so obviously not all Israel is toast. As in the days of Elijah, God has chosen a "remnant" in his graciousness. So far Paul sounds a lot like he did in Romans 9. God gave the unbelieving in Israel a "sluggish spirit" so that they would not see or hear the message (11:8-9, NRSV). "Their eyes are darkened so they cannot see" (11:10).
However, then he goes on. "Did they stumble so as to fall beyond recovery?" (11:11). Here is the key to understanding what is really going on here. Even those "predestined for disbelief" can come back! This is certainly not the kind of predestination of some Christian traditions. Indeed, John Calvin logically reasoned that if God decides who will be saved, then you must remain saved till the end. God does not change his mind but has made the decision from all eternity and your will has no part in it.
The predestined in this scheme cannot change places.  Either God has chosen you or he has not. But in the rest of Romans 11, Paul begins to chart out the eventual return of ethnic Israel from its current "hardness of heart." What is going on right now, Paul says, is that God had a plan to bring the Gentiles to salvation. Israel's current hardness is all part of the plan. First, God is using their hardness of heart to bring the Gentiles in. Then he will bring the Jews back in again too.
Clearly Paul is trying to make sense of what must have been a troubling phenomenon among the earliest Christians: Gentiles seemed much more receptive to the Christian message than the Jews themselves did. Paul chalks it up to the mystery of God's will. This is all part of the plan. If you think of a tree, God has cut out a good number of the "natural branches" and grafted in some Gentile branches that were not part of the original tree (11:17). He is making the natural branches jealous (11:11).
But this is of course not a matter for boasting, as if the Gentile branches are "eternally secure." If God did not spare the natural branches, he certainly will not spare the granted in branches if they were to become arrogant about their new identity (11:21). Clearly these are not the sorts of things we would expect Paul to say if the Calvinist interpretation of Romans 9 were correct. The destiny of each type of branch is reversable. Indeed, the way the branches conduct themselves has a direct bearing on whether they get to stay in the tree at all. In short, Paul sees one's location in the tree as contingent on human response. Most of ethnic Israel is currently out because of unbelief (11:20), but they can come back in if they start believing. Many Gentiles are in because they have believed, but if they become arrogant they will be grafted back out.
 It is true that, just as in Romans 9, Paul is not talking specifically about individuals in Romans 11. Paul is talking about the direction of Israel as a whole. Someone might suggest, then, that while the direction of Israel as a whole might change, Paul's plan for specific individuals must logically remain the same. But can you see how far removed this entire discussion is from what Paul is actually talking about? Romans 9-11 is focused on individuals but on the fate of Israel.